 /*
  * $Header: /cvshome/build/org.osgi.service.cm/src/org/osgi/service/cm/ManagedServiceFactory.java,v 1.12 2006/07/11 00:54:03 hargrave Exp $
  *
  * Copyright (c) OSGi Alliance (2001, 2006). All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.osgi.service.cm;

 import java.util.Dictionary ;

 /**
  * Manage multiple service instances.
  *
  * Bundles registering this interface are giving the Configuration Admin service
  * the ability to create and configure a number of instances of a service that
  * the implementing bundle can provide. For example, a bundle implementing a
  * DHCP server could be instantiated multiple times for different interfaces
  * using a factory.
  *
  * <p>
  * Each of these <i>service instances </i> is represented, in the persistent
  * storage of the Configuration Admin service, by a factory
  * <code>Configuration</code> object that has a PID. When such a
  * <code>Configuration</code> is updated, the Configuration Admin service
  * calls the <code>ManagedServiceFactory</code> updated method with the new
  * properties. When <code>updated</code> is called with a new PID, the Managed
  * Service Factory should create a new factory instance based on these
  * configuration properties. When called with a PID that it has seen before, it
  * should update that existing service instance with the new configuration
  * information.
  *
  * <p>
  * In general it is expected that the implementation of this interface will
  * maintain a data structure that maps PIDs to the factory instances that it has
  * created. The semantics of a factory instance are defined by the Managed
  * Service Factory. However, if the factory instance is registered as a service
  * object with the service registry, its PID should match the PID of the
  * corresponding <code>Configuration</code> object (but it should <b>not </b>
  * be registered as a Managed Service!).
  *
  * <p>
  * An example that demonstrates the use of a factory. It will create serial
  * ports under command of the Configuration Admin service.
  *
  * <pre>
  *
  * class SerialPortFactory
  * implements ManagedServiceFactory {
  * ServiceRegistration registration;
  * Hashtable ports;
  * void start(BundleContext context) {
  * Hashtable properties = new Hashtable();
  * properties.put( Constants.SERVICE_PID,
  * &quot;com.acme.serialportfactory&quot; );
  * registration = context.registerService(
  * ManagedServiceFactory.class.getName(),
  * this,
  * properties
  * );
  * }
  * public void updated( String pid,
  * Dictionary properties ) {
  * String portName = (String) properties.get(&quot;port&quot;);
  * SerialPortService port =
  * (SerialPort) ports.get( pid );
  * if ( port == null ) {
  * port = new SerialPortService();
  * ports.put( pid, port );
  * port.open();
  * }
  * if ( port.getPortName().equals(portName) )
  * return;
  * port.setPortName( portName );
  * }
  * public void deleted( String pid ) {
  * SerialPortService port =
  * (SerialPort) ports.get( pid );
  * port.close();
  * ports.remove( pid );
  * }
  * ...
  * }
  *
  * </pre>
  *
  * @version $Revision: 1.12 $
  */
 public interface ManagedServiceFactory {
     /**
      * Return a descriptive name of this factory.
      *
      * @return the name for the factory, which might be localized
      */
     public String getName();

     /**
      * Create a new instance, or update the configuration of an existing
      * instance.
      *
      * If the PID of the <code>Configuration</code> object is new for the
      * Managed Service Factory, then create a new factory instance, using the
      * configuration <code>properties</code> provided. Else, update the
      * service instance with the provided <code>properties</code>.
      *
      * <p>
      * If the factory instance is registered with the Framework, then the
      * configuration <code>properties</code> should be copied to its registry
      * properties. This is not mandatory and security sensitive properties
      * should obviously not be copied.
      *
      * <p>
      * If this method throws any <code>Exception</code>, the Configuration
      * Admin service must catch it and should log it.
      *
      * <p>
      * When the implementation of updated detects any kind of error in the
      * configuration properties, it should create a new
      * {@link ConfigurationException} which describes the problem.
      *
      * <p>
      * The Configuration Admin service must call this method asynchronously.
      * This implies that implementors of the <code>ManagedServiceFactory</code>
      * class can be assured that the callback will not take place during
      * registration when they execute the registration in a synchronized method.
      *
      * @param pid The PID for this configuration.
      * @param properties A copy of the configuration properties. This argument
      * must not contain the service.bundleLocation" property. The value
      * of this property may be obtained from the
      * <code>Configuration.getBundleLocation</code> method.
      * @throws ConfigurationException when the configuration properties are
      * invalid.
      */
     public void updated(String pid, Dictionary properties)
             throws ConfigurationException;

     /**
      * Remove a factory instance.
      *
      * Remove the factory instance associated with the PID. If the instance was
      * registered with the service registry, it should be unregistered.
      * <p>
      * If this method throws any <code>Exception</code>, the Configuration
      * Admin service must catch it and should log it.
      * <p>
      * The Configuration Admin service must call this method asynchronously.
      *
      * @param pid the PID of the service to be removed
      */
     public void deleted(String pid);
 }

